compiz crashed with SIGSEGV in nux::GpuDevice::GetGpuInfo()

[Zach Avallone]

1) Using 11.04 (Unity)
2) I was trying to enable the Desktop Cube through the system setting menu, there were a series of prompts about enabling/disabling certain plug-ins (Open GPL, maybe?)
3) I expected to enable desktop cube without Unity crashing.
4) Error message, reporting option, and then Unity crashed.

ProblemType: Crash
DistroRelease: Ubuntu 11.04
Package: libnux-0.9-0 0.9.44-0ubuntu1
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic x86_64
Architecture: amd64
Date: Fri Apr 15 00:04:17 2011
ExecutablePath: /usr/bin/compiz
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release amd64 (20101007)
ProcCmdline: compiz
ProcEnviron:
 LANGUAGE=en_US:en
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SegvAnalysis:
 Segfault happened at: 0x7f9241cd4050 <_ZN3nux9GpuDevice10GetGpuInfoEv>: mov 0xc0(%rdi),%rax
 PC (0x7f9241cd4050) ok
 source "0xc0(%rdi)" (0x000000c0) not located in a known VMA region (needed readable region)!
 destination "%rax" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: nux
StacktraceTop:
 nux::GpuDevice::GetGpuInfo() () from /usr/lib/libnux-graphics-0.9.so.0
 nux::GpuDevice::CreateSystemCapableTexture() () from /usr/lib/libnux-graphics-0.9.so.0
 PanelMenuView::Refresh() () from /usr/lib/compiz/libunityshell.so
 PanelMenuView::OnActiveWindowChanged(_BamfView*, _BamfView*) () from /usr/lib/compiz/libunityshell.so
 g_closure_invoke () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
Title: compiz crashed with SIGSEGV in nux::GpuDevice::GetGpuInfo()
UpgradeStatus: Upgraded to natty on 2011-04-15 (0 days ago)
UserGroups: adm admin cdrom dialout lp lpadmin plugdev sambashare

[Apport retracing service (apport)]

StacktraceTop:
 nux::GpuDevice::GetGpuInfo (this=0x0) at ./GpuDevice.cpp:715
 nux::GpuDevice::CreateSystemCapableTexture (this=0x0) at ./GpuDevice.cpp:985
 PanelMenuView::Refresh (this=0x196c500) at /build/buildd/unity-3.8.8/src/PanelMenuView.cpp:614
 PanelMenuView::OnActiveWindowChanged (this=0x196c500, old_view=<value optimized out>, new_view=0x0) at /build/buildd/unity-3.8.8/src/PanelMenuView.cpp:781
 g_closure_invoke (closure=0x196da80, return_value=0x0, n_param_values=3, param_values=0x191c0a0, invocation_hint=0x7fffd2378c50) at /build/buildd/glib2.0-2.28.5/./gobject/gclosure.c:767

[Zach Avallone (zachary-avallone)]

Quick follow-up

Unity never started up correctly after this error.
Top bar and side launcher never loaded.
Keyboard commands (Alt-F2) did not work either.
Only function was right-click, create custom launcher (which opened a firefox window that could not be closed).

Ubuntu "classic" would also load incorrectly
Every open window did not have a top window bar (Close, Min, Max).
All windows were stuck in the top left corner of the screen.
Desktop workspace switcher did not function.

This was in a partition that I regularly use, so I wiped and re-installed 10.10
Let me know if you need me to try to re-create.

[Sebastien Bacher (seb128)]

what video card and driver do you use?

[Zach Avallone (zachary-avallone)]

Video Card: Intel Corporation Mobile 4 Series Chipset Integrated Graphics
Controller (rev 07)

Driver: Whatever the default driver is in 11.04. I'm not sure exactly what
driver was being used, I did not change any hardware or driver settings
before crash.

On Fri, Apr 15, 2011 at 11:49 AM, Sebastien Bacher <email address hidden>wrote:

> what video card and driver do you use?
>
> --
> You received this bug notification because you are a direct subscriber
> of the bug.
> https://bugs.launchpad.net/bugs/761368
>
> Title:
> compiz crashed with SIGSEGV in nux::GpuDevice::GetGpuInfo()
>
> Status in “nux” package in Ubuntu:
> New
>
> Bug description:
> 1) Using 11.04 (Unity)
> 2) I was trying to enable the Desktop Cube through the system setting
> menu, there were a series of prompts about enabling/disabling certain
> plug-ins (Open GPL, maybe?)
> 3) I expected to enable desktop cube without Unity crashing.
> 4) Error message, reporting option, and then Unity crashed.
>
> ProblemType: Crash
> DistroRelease: Ubuntu 11.04
> Package: libnux-0.9-0 0.9.44-0ubuntu1
> ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
> Uname: Linux 2.6.38-8-generic x86_64
> Architecture: amd64
> Date: Fri Apr 15 00:04:17 2011
> ExecutablePath: /usr/bin/compiz
> InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release amd64
> (20101007)
> ProcCmdline: compiz
> ProcEnviron:
> LANGUAGE=en_US:en
> LANG=en_US.UTF-8
> SHELL=/bin/bash
> SegvAnalysis:
> Segfault happened at: 0x7f9241cd4050 <_ZN3nux9GpuDevice10GetGpuInfoEv>:
> mov 0xc0(%rdi),%rax
> PC (0x7f9241cd4050) ok
> source "0xc0(%rdi)" (0x000000c0) not located in a known VMA region
> (needed readable region)!
> destination "%rax" ok
> SegvReason: reading NULL VMA
> Signal: 11
> SourcePackage: nux
> StacktraceTop:
> nux::GpuDevice::GetGpuInfo() () from /usr/lib/libnux-graphics-0.9.so.0
> nux::GpuDevice::CreateSystemCapableTexture() () from
> /usr/lib/libnux-graphics-0.9.so.0
> PanelMenuView::Refresh() () from /usr/lib/compiz/libunityshell.so
> PanelMenuView::OnActiveWindowChanged(_BamfView*, _BamfView*) () from
> /usr/lib/compiz/libunityshell.so
> g_closure_invoke () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
> Title: compiz crashed with SIGSEGV in nux::GpuDevice::GetGpuInfo()
> UpgradeStatus: Upgraded to natty on 2011-04-15 (0 days ago)
> UserGroups: adm admin cdrom dialout lp lpadmin plugdev sambashare
>
> To unsubscribe from this bug, go to:
> https://bugs.launchpad.net/ubuntu/+source/nux/+bug/761368/+subscribe
>

[Loïc Molinari (loic.molinari)]

It happens to me sometimes when I enable/disable a plugin in ccsm, and always when I disable the Unity plugin itself. Before my last fixes pushed to partly fix #685552, it was crashing earlier in sigc::signal_base::impl().

Not that when a plugin is added/removed, all the plugins loaded are destroyed and recreated. After studying a bit the reason of that crash, it seems like the PanelMenuView is not freed after the Unity plugin is destroyed, the signals connected are not disconnected and can still be called. Here PanelMenuView::OnActiveWindowChanged is called even though most of the other objects have been destroyed, in the Refresh method it's crashing attempting to create a texture from a GpuDevice which is NULL (already destroyed).

To fix that issue, IMO we should make sure the PanelMenuView is correctly freed at the unity plugin destruction.

[Loïc Molinari (loic.molinari)]

since unity-3.8.10 which includes the Panel fixes I was pointing earlier, I've not been able to reproduce that crash anymore.

[Didier Roche-Tolomelli (didrocks)]

Let's close it then, thanks Loïc!